Definition and use: What best describes transgenic plants and one of their established applications?

Introduction / Context:
Transgenic plants are central to modern biotechnology. They carry genes introduced from other species or engineered versions of their own genes, enabling traits from pest resistance to pharmaceutical protein production.

Given Data / Assumptions:

• Transgenic status requires stable integration and expression of a foreign or modified gene.
• Plants have been used to produce complex human proteins, including antibodies.
• The question asks for an accurate definition and example application.

Concept / Approach:
Option (a) states the defining feature—foreign gene presence. Option (b) reflects an established application—plantibodies for diagnostics or therapy. Together, they capture what transgenic plants are and how they are used.

Step-by-Step Solution:

Verification / Alternative check:
Multiple studies demonstrate antibody assembly in plants (heavy and light chains) with proper glycosylation engineering, confirming feasibility.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing cisgenic (from crossable species) with transgenic; both are GM, but the question focuses on foreign gene presence and application.

Final Answer:
Both (a) and (b).